Ray, Another (more general) way is to implemement these types of constraints through Lagrangian multipliers. In your case minimize f(x,p0,p1,p2,p3,p4) + mu * (p0+p4-C) where you have now an additional variable mu to be minimized. A possible adavantage over parameter substitution is that you will get the error matrix for the p's taking the constraint into account. Eddy > > Hi Ray, > Fitting with constraints is not implemented. > Reduce the number of parameters from 5 to 4 and in your function > define an internal variable p4=C-p0 > > Rene Brun > > > On Tue, 31 Oct 2000, Ray Fliller III wrote: > > > > > Hello Rooters, > > > > Is it posible to fit a function and impose an equation of constraint > > between the variables, for example: > > > > I have a function f(x,p0,p1,p2,p3,p4) where the p's are my fitting > > parameters. Is there a way to impose on the fit the constraint that > > p0+p4=C where C is some constant?? Or some other such constraint?? > > > > Thanks. > > > > ============================================================================== > > Ray Fliller: rfliller@bnl.gov Office Phone: (631)-344-6124 > > C-A Accelerator Physics > > Building 911 > > Brookhaven National Lab > > Upton, NY 11973 Office: Room 211 > > ============================================================================== > > > Eddy A.J.M. Offermann Renaissance Technologies Corp. Route 25A, East Setauket NY 11733 e-mail: eddy@rentec.com http://www.rentec.com
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